SYNOPSIS:
    BFS startvoxel [onlysteps]

DESCRIPTION:
    Do a filling operation based on breadth first search which
    is tolerant to faulty borders containing gaps.
    The parameters for the BFS function are not all specified
    on the commandline, as they are changed rarely between fill
    operations. Instead the following variables influence the
    behaviour of th BFS command:
    /module.internal.bfs.distance/ sets the maximum allowed
        hole size. That is, holes of a diameter of less than the
        value given here will not cause the fill operation to spill
        out.
    /module.internal.bfs.pocketsize/ sets the maximum size
        allowed for "pockets" that might be behind a hole of the above
        diameter. Reasonable values are about (2*distance)^2.
    /module.internal.bfs.pocketloops/ sets how many attempts
        are made to fill side channels that are caused by such
        pockets. Reasonable values range from 0-10 with 3 being a
        good default value.
    /module.internal.bfs.pocketdepth/ sets the maximum depth
        allowed for "pockets" that might be behind a hole of the above
        diameter. Reasonable values are about 2*dist.
        Note, that this differs from pocketsize. Pocketdepth cares
        about how _long_ a structure is, while pocketsize cares about
        what _area_ the cross-sections of the structure with the
        elementary planes cover.
    /module.internal.bfs.fillcolor/ sets the color that is
        used for BFS filling. This defaults to 6 (yellow) for historical
        reasons. If set to -1, BFS will behave like most other commands
        and use the colorize setting of the current view.
        This can be controlled idependently, as one will often want to
        use another color for drawing barriers to stop spillout, if
        large gaps exist.
